(a) Field of the Invention
The present invention relates to LED lamp technology and more particularly to an LED lamp bulb, which comprises a heat sink, a radiation fin set, an insulative lamp bulb base, a light-transmission bulb shell, and a retainer rim securing the radiation fin set and the light-transmission bulb shell to prevent relative rotation therebetween.
(b) Description of the Prior Art
A conventional LED lamp bulb comprises a heat sink, a radiation fin set, an insulative lamp bulb base, LEDs or a substrate carrying multiple series of LEDs, and a light-transmission bulb shell. The radiation fin set is bonded to the heat sink, having its bottom side affixed to the insulative lamp bulb base. The insulative lamp bulb base is an externally threaded hollow member provided with a metal conducting ring contact. Waste heat produced during operation of the LEDs is transferred to the heat sink and the radiation fin set for dissipation into the outside open air.
The aforesaid radiation fin set comprises a plurality of radiation fins arranged in a radial configuration. In order to prevent the sharp top edges of the radiation fins from injuring people touching them, a ring cap may be used to cover the sharp top edges of the radiation fins. The ring cap is simply capped on the sharp top edges of the radiation fins. It may be forced to rotate relative to the radiation fin set or to fall out of the radiation fin set accidentally by an external force. Further, the light-transmission bulb shell is bonded to the ring cap with an adhesive. However, the adhesive deteriorates after a long use, losing its adhesion power. When this condition occurs, the light-transmission bulb shell will fall from the ring cap. Therefore, this light-transmission bulb shell mounting method is not a satisfactory method.
Further, the light-transmission bulb shell can be made to have a flat profile. Alternatively, the light-transmission bulb shell can have a semi-spherical shape, simulating an incandescent lamp bulb. Conventional LED lamp bulbs are seen in Taiwan Utility Model Numbers M389826; M419035; M353292; M400660; M413817; M422646; M421458; M381724.